SFI SYSTEM, Diagnostic DTC:P2121

DESCRIPTION

Refer to DTC P2120.

Click here

MONITOR DESCRIPTION

The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal position sensor has 2 sensor elements and 2 signal outputs: VPA and VPA2. VPA is used to detect the actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA. When the difference between the output voltages of VPA and VPA2 deviates from the standard, the ECM determines that the accelerator pedal position sensor is malfunctioning. The ECM illuminates the MIL and stores the DTC.

MONITOR STRATEGY

CONFIRMATION DRIVING PATTERN

1. Connect the GTS to the DLC3.

2. Turn the ignition switch to ON and turn the GTS on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the GTS on [A].

6. Wait for 5 seconds after turning the ignition switch to ON.

7. Operate the accelerator pedal in accordance with the following procedure [B].




1. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sens. No. 1 Volt %, and Accel Sens. No. 2 Volt %.

2. Slowly depress the accelerator pedal until Accel Sens. No. 1 Volt % is approximately 30% and Accel Sens. No. 2 Volt % is approximately 46%, then slowly release the accelerator pedal.

8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

9. Read the pending DTCs.

   Tech Tips

   
   

   • If a pending DTC is output, the system is malfunctioning.

   • If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

11. Input the DTC: P2121.

12. Check the DTC judgment result.

    GTS Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    N/A	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips

    
    

    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform steps [B] and [C] again.

FAIL-SAFE

The accelerator pedal position sensor has 2 (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the 2 sensor circuits and switches to fail-safe mode. In fail-safe mode, the functioning circuit is used to calculate the accelerator pedal opening angle to allow the vehicle to continue driving. If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal as being fully closed. In this case, the throttle valve remains closed as if the engine is idling.

If a pass condition is detected and then the ignition switch is turned off, the fail-safe operation stops and the system returns to normal.

WIRING DIAGRAM

Refer to DTC P2120.

Click here

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2121)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

   5. Read the DTCs.

      
      Powertrain > Engine and ECT > Trouble Codes

      Result
      Result Proceed to DTC P2121 is output A DTC P2121 and other DTCs are output B

      Tech Tips

      If any DTCs other than P2121 are output, troubleshoot those DTCs first.

   
   

   B

   GO TO DTC CHART Click here

   A

2. READ VALUE USING GTS (ACCEL SENSOR OUT NO. 1 AND NO. 2)

   
   
   1. 

      *a	Fully Depressed
      *b	Fully Released

      Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / Accel Sensor Out No. 1 and Accel Sensor Out No. 2.

      
      Powertrain > Engine and ECT > Data List

      Tester Display
      Accel Sensor Out No.1
      Accel Sensor Out No.2

   5. Read the values displayed on the GTS.

      Standard Voltage
      Accelerator Pedal Operation Accel Sensor Out No. 1 Accel Sensor Out No. 2 Fully Released 0.5 to 1.1 V 1.2 to 2.0 V Fully Depressed 2.6 to 4.5 V 3.4 to 4.75 V

      Result
      Proceed to OK NG

   
   

   OK

   CHECK FOR INTERMITTENT PROBLEMS Click here

   NG

3. REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY

   
   

   1. Replace the accelerator pedal sensor assembly.

      Click here

      Result
      Proceed to NEXT

   
   

   NEXT

4. CHECK WHETHER DTC OUTPUT RECURS (DTC P2121)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Clear the DTCs.

      
      Powertrain > Engine and ECT > Clear DTCs

   5. Turn the ignition switch off and wait for at least 30 seconds.

   6. Turn the ignition switch to ON and turn the GTS on.

   7. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.

   8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

   9. Read the DTCs.

      
      Powertrain > Engine and ECT > Trouble Codes

      Result
      Result Proceed to DTC P2121 is output A DTC is not output B

   
   

   A

   REPLACE ECM Click here

   B

   END